Method of making engine-cylinders.



M. FISCHER.

MBTHOD or MAKING ENGINE GYLINDERS.

APPLIOATION PILED JUNE 8, 1914.

Patented Nov. 17, 1914.

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; STATES PATENT OFFICE,

MARTIN FISCHER, OF ZURICH, SWITZERLAND, ASSIGNOR TO FISCHER MOTOR CORPO- RATION, A CORPORATION OF NEW YORK.

METHOD OF MAKING ENGINE-CYLINDERS.

Specificaton of Letters Patent.

Patented Nov. 1 7, 1914.

Application filed June 8, 1914. Serial No. 843,(553.

To all whom it may concem Be it known that I, MARTIN FISCHER, a citizen of Switzerland, a resident of Zurich, in the Canton of Zurich, Switzerland, have invented certain new and useful Improvements in the Method of Making Engine-Gylinders, of which the following is a specification, reference being had to the accompanying drawings, made a part hereof.

My invention relates to the method of making engine cylinders and more particularly to the bore of the same, and providing valve seats in the walls of the cylinders.

Among other objccts, my method aiiords extreme accuracy with the minimum of eX- pense.

In a particular form of engine where my method is especially applicable, the engine cylinder has a longitudinal recess in the side, opening into the cylinder, in which recess a. valve is located and reciprocates longitudinally. In a prior application filed by me January 12, 1912, I show a cylinder with integral head. A further development of that type of engine embodied a detachable head so that the main cylinder casting is open at both ends and therefore permits boring tools to be put through the cylinder and supported close to each end. In this case I provide for the boring of the valve recesses as hereinafter described, with reference to the drawings forming a part hereof, in which:

Figure l is a plan of the top of a cylinder. Fig. 2 is a vertical section of the main cylinder casting. Fig. 3 is a vertical section oi one end of a cylinder. Fig. i is a Vertical section of part of a cylinder showing the removable cylinder head in position.

In the drawings, A is the cylinder casting; B the removable cylinder head; C is the portion of the cylinder wall concentric with the piston; D-D are grooves runnnglongitudinally of the cylinder and may be either one or more, depending upon the number of slide Valves of this character to be used in the design; E is a temporary web; E' is a temporary frame.

I will now describe my method of machining cylinders with reference to the particular form shown in the drawings, which is a design oi' cylinder made to use slide valves reciprocating along the inner side of the cylinder wall and having a crescent cross-section. In this form the main cylinder casting requires longitudinal recesses or grooves in the inner wall running the length of the main cylinder casting, although the method will be equally applicable if the grooves are not of the same extent, or when modified in other respects.

The main casting A is made with cores running the length of the casting, parallel to the axis of the cylinder, to leave four spaces F-F and G-G. Between these spaces there remains a web E which extends from opposite sides of the cylinder interior in part circular form. These cores, therefore, leave the walls C--C of the cylinder, which are to be machined later concentric with the piston; and causing G-G to leave a recess D, which is later to be machined to accommodate the outside or back of the slide valve. The web E is formed in the casting so that a boring tool used to form the seat D will be cutting metal throughout its rotation, and will therefore cut or bore a true hole, which would not be the case if the tool had a one-sided cut, that is, cutting the metal only during part of its revolution. The cores are, of course, made of proper size to allow for the machining of the surfaces and leave the web E of sufficient strcngth to support the strain and prevent any yielding of the boring bar.

As shown in Fig. 2, this web support of the recess runs throughout the cylinder; while in Fig. 3 a modification is shown wherein E' is a frame work at the end of the cylinder, which may be put at either or both ends, and afl ords support for a collar or guide for the boring bar. This arrangement is suitable when extreme accuracy throughout the length of the groove D is not necessary, but 'it is desired to insure accuracy close to each end of the cylinder. In either case the web E or the frame E' is cut off after the slide Valve recesses have been turned, bored or ground, and then the boring of the cylinder walls proper, to finish surfaces C--C is accomplished in any manner desired. By this method it is possible to insure perfect accuracy and interchangeability ot' the parts for cylinders of this design.

It will be seen that my method may be employed in other cases than the particular a daptation shown and described, but

lVhat I claim and desire to secure by Letters Patent is:

1. A method of making engine cylinders consisting of casting a cylinder with a temporary guide wall forming a cutt-ing support for a tool eccentrc to the main cylinder bore, machining the eccentrc bore, then cutting away the temporary supporting wall and finish boring the main cyliider walls.

2. A method of making engine cylinders having a recess cut in the inner wall and open to the cylinder proper, consisting of casting a cylinder provided with a temporary frame across the cylinder bore, using` said frame as a guide for the boring or other nachining tool to finish the surface of the recess in the cylinder, cutting away said frame and then machining the bore of the cylinder proper.

3. A method of making engine cylinders adapted to use a crescent-shaped slide valve, consisting of casting a cylinder by corng said cylinder to leave a substantially X- shaped temporary frame within the cylinder opening, utilizing said frame to guide a tool for machining the curved recesses in the inner wall o'the cylinder, cuttng out said temporary frane and finish machining the cylinder proper.

4:. A method of making engine cylinders consisting of casting a cylnder with a temporary tool-supporting frane cast integrally therewith and having in the cross-section normal to the aXs oi' the cylnder, a substantally X-shaped section, either half of said X-shaped section of frame being curved to form with the eontiguous portion of the casting a circular guide of diameter slightly in excess of the radius of the cylinder, utilizing said temporary :Erame to guide in the Copie of this patent may be obtained for boring of recesses in the sides of the cylinder, cutting away said temporary frame, and thereupon finish-machining the main bore of the cylnder.

5. A method of machining a recess on the interior of a cylinder consisting in casting said cylinder with a web longtudinally thereof, adapted to hold and guide a tool while machinng said recess thereupon cutting away said temporary web 'and finishmachining the interior ot' the cylinden 6. A method of machining a recess on the interiorof a cylinder, consisting of including in the casting a portion of Supplementary material with relation to the interier of the cylinder, whereby a tool will have its cutting edge engagng metal throughout its action, thereupon cutting away said supplenentary portion of the casting and finish-niachining the interior of the cylinder.

7. A method of machning a recess on the interier of a cylinder, co-nsisting in including in the original casting a temporary portion adapted to support a tool while machining said recess, machining the recess, thereupon cutting away said temporary portion and finish-machinng the interior of the cylinder. I v

In testimony whereof I have signed my name to this specificaton, in the presence of two subscribng witnesses, this 11th day of May, 1914.

MARTIN FI SCHER;

Htnesses CON BAD SIGG, AUGUST RUEGG.

five cents each. by addressng the Commsacer of Patents, Washington, D. G." 

